I hope BTC direct investment in the ICO will be an option.
It won't be. If you want to participate in the ICO, exchange the amount you want to buy from BTC to ETH.
There is huge interest in this project, even if they want to the slow transaction rate of Bitcoin at the moment won't encourage it. I have a transaction for more than 24hrs now still unconfirmed. This is getting annoying and something need to be done very fast